1. Field of the Invention
The present invention relates to a transistor for a semiconductor integrated circuit device and fabricating method therefor, and more particularly to a vertical type transistor for a semiconductor integrated circuit device and fabricating method thereof, which is capable of high integration and has a new structure.
2. Description of the Prior Art
As generally known in the art, a semiconductor integrated circuit device generally employs a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) as a unit transistor, and integrates lots of unit transistors into one identical semiconductor substrate to embody an integrated circuit. The transistors as explained above have horizontal type structures, and they rely on the lithography more and more and effective channels thereof are remarkably weakened along with the increase of the integration degree of the semiconductor device to result in the production of following several problems.
For example, as the channel of the transistor becomes shorter, there occurs a short channel effect that threshold voltages decrease or a reverse channel effect that threshold voltages increase, and a gate induced drain leakage (GIDL) phenomenon occurs in a semiconductor substrate using a thin gate oxide film.
Further, a punch through phenomenon increases, and when the transistor is not activated, leakage current (IOFF) increases, also junction capacitance in a source/drain region increases, and change of the threshold voltage has occurred.
Additionally, various studies and developments have been performed in order to accomplish high current drivability, ultra high speed, and ultra low powers.